JP2663944B2 - Manufacturing method of dielectric resonator material - Google Patents

Description

The present invention relates to a method for manufacturing a dielectric resonator material for microwaves. [Related Art] A dielectric resonator material for satellite communication or the like is desired to have a high Q value. Ba (Zn _1/3 Nb
There are perovskite-type ceramics such as _2/3 ) O ₃ and Ba (Zn _1/3 Ta _2/3 ) O ₃ and have a good Q value. However, these ceramic materials are difficult to fire in a general dry method, so that it is difficult to obtain the original characteristics. That is, the chemical formula Ba (Zn _1/3 Nb _{x / 3} Ta _{(2-X) / 3} )
O ₃ , perovskite-type ceramics represented by 0 ≦ x ≦ 2 (hereinafter BZNT-based ceramics or simply
BZNT) is generally used as a raw material powder, for example.
BaCO ₃ powder, ZnO powder, Nb ₂ O ₅ powder, Ta ₂ O ₅ powder, etc.
After being blended so as to have a BZNT composition, this is mixed by a dry method using a ball mill or the like, and then calcined at, for example, about 1200 ° C. to obtain a BZNT powder. It is finally obtained by firing. In order to increase the resonance characteristics, that is, the Q value, of the obtained BZNT ceramic, it is necessary to increase the density of the ceramic. In a mere dry method in which a powder is pressed and then fired into a ceramic, the density of the ceramic strongly depends on the packing density in the pressed state before firing. Therefore, in order to increase the density of ceramics, it is necessary to increase the packing density. For that purpose, it is necessary to further refine the calcined BZNT powder before pressing. However, in the case of the raw material powder as described above, the tendency of agglomeration between the particles is rapidly increased due to the progress of the refinement, so that the refinement is saturated, and after calcination,
The refinement of BZNT powder is also saturated. Therefore, the conventionally obtained BZNT calcined powder was at least 1-2 μm at least. Thus, there has been a strong demand for a method of manufacturing a dielectric resonator material having a higher Q value by further reducing the size of BZNT powder. [Problems to be Solved by the Invention] The object of the present invention is to solve the problem in the dry method, to produce a modified oxide powder of submicron class having good dispersibility of particles by a wet method, By mixing and calcining the powder by a simple dry method to produce a raw material powder having the same composition as the originally desired ceramics, it is easy to bake and produce a dielectric resonator material for microwaves with good characteristics. Is to provide a way to [Means for Solving the Problems] The purpose of the above is to make the chemical formula Ba (Zn _1/3 Nb _{x / 3} Ta
_{(2-x) / 3} ) A method for producing a dielectric resonator material having a perovskite composition represented by O ₃ and 0 ≦ x ≦ 2, wherein (1) an appropriate amount of at least one metal component other than Zn in the chemical formula and Zn A solution containing an appropriate amount of at least one metal component other than Ba in the chemical formula and Ba, and a solution containing an appropriate amount of at least one metal component other than Nb and Nb in the chemical formula. (2) hydrolyzing the solution to form a sol, drying the sol, and then calcining at 700 to 1300 ° C. to form a calcined product; Mixing the compound of the remaining components of the perovskite composition and calcining at 700 to 1300 ° C. to form a calcined powder; and (4) molding the calcined powder and calcining at 1200 to 1700 ° C. Attained by a method for manufacturing a dielectric resonator material, comprising the steps of: That. The present inventor has determined that the above steps (1) and (2) including the wet process
Submicron modified powder (modified oxide powder) as a calcined product by, for example BaZnO ₂ powder is obtained, this modified powder may very dispersibility, conventional raw material powder as used provided they have not been modified example BaCO ₃ It has been found that aggregation of particles inevitably generated in powder, ZnO powder and the like is unlikely to occur. In addition, the present inventors, by step (3), the compound of the modified powder (BaZnO ₂ powder in the above case) and the remaining component (in this case, Nb and / or Ta) of the target perovskite composition (for example, Nb ₂ O ₅ , Ta ₂ O ₅ etc.), this mixed powder itself does not have cohesiveness, and if calcined, sub-micron grade BZNT calcined powder with good dispersibility is also obtained. Even if operations such as HIP (for example, hot gas pressure sintering) are omitted, the perovskite-type BZNT ceramic obtained by forming and firing it in step (4) has an extremely high density and has a dielectric resonator. It has been found that the material has a significantly improved Q value. In the present invention, Ba of the above chemical formula and (Zn _1/3 Nb _{x / 3} Ta
The molar ratio with _{(2-x) / 3} does not necessarily have to be exactly 1 and may be slightly larger or smaller than 1 as long as the perovskite crystal structure is substantially maintained. The solution in step (1) is an aqueous solution or an alcohol solution. The solution is prepared by adding a compound powder of at least one metal component other than Zn, Ba, or Nb in the above chemical formula to Zn, B
a, or dissolved in a solution containing Nb, respectively,
Conversely, the latter compound powder is dissolved in the solution containing the former, or both are prepared and mixed as solutions containing the respective components, or both are prepared as compound powders and are put together in water or alcohol. Dissolution, either or a combination thereof. As a compound for preparing a solution containing Zn,
For example, zinc chloride, zinc sulfate, zinc nitrate, zinc acetate and the like are used. These Zn compounds may be used alone,
Alternatively, two or more kinds may be used together as long as they do not affect each other. As a compound for preparing a solution containing Ba, for example, barium chloride, barium chlorate, barium perchlorate, barium nitrate, barium acetate, barium ethylate, barium isopropylate, or the like is used. One of these Ba compounds may be used alone, or two or more thereof may be used together as long as they do not affect each other. As a compound for preparing a solution containing Nb, niobium chloride, niobium methoxide, niobium ethylate, sodium niobate and the like are used. These Nb
The compounds may be used alone or in combination of two or more as long as they do not affect each other. The “appropriate amount” in the step (1) is an amount suitable for suppressing the aggregation of the sol generated in the step (2), and varies depending on the compound used for preparing the solution. The sol generated in the step (2) is recovered by filtration and washing, and then dried. The calcined temperature of the dried sol is 700 to 1300 ° C. When the calcination temperature is lower than 700 ° C., agglomeration occurs remarkably, and when it exceeds 1300 ° C., the particles tend to be coarse. The thus obtained calcined product is mixed with a deficiency of a component as a perovskite composition. In the above case, for example, BaCO ₃ powder can be further mixed so that a desired perovskite composition is obtained. In order to obtain the effect of preventing aggregation as a mixture, at least one of the raw material powders may be a submicron-grade modified powder formed in the steps (1) and (2). Therefore,
As the compound of the remaining constituent components to be mixed in the step (3), a conventional commercially available raw material powder may be used, and the submicron-class powder formed in the same manner as described above in the steps (1) and (2) may be used. Denatured powder may be used. All of the commercially available raw material powders used in step (3) need to have a submicron class particle size. The calcination temperature of the mixture (step (3)) is 700 ° C.
A perovskite structure is formed from the vicinity, and when calcined at 1300 ° C. or more, the calcined powder particle size becomes large and the calcining characteristics are remarkably deteriorated. Therefore, it is necessary to be in the range of 700 to 1300 ° C. The powder obtained in this way is molded. The sintering temperature varies depending on the type of the constituent components, similarly to the calcination temperature of the mixture, but is generally in the range of 1200 to 1700 ° C. 1200
If it is lower than ℃, sintering is insufficient and high density cannot be obtained.
If it exceeds, the particles become coarse or the volatile elements volatilize and are lost. In order to improve the sinterability and characteristics in the firing after molding (step (4)), Zr, Mg, Sc, and Zr, Mg, Sc, may be used as necessary in at least one of the steps (2) and (3). H
f, Th, W, Nb, Ta, Cr, Mo, Ti, Mn, Fe, Co, Ni, Cd, Al, Sn, As, Bi, Z
A trace amount of one or more elements of n and Sr is added. The auxiliaries can also be added in trace amounts in the form of one or more of BaZrO ₃ , BaSnO ₃ , SnTiO ₃ and BaTiO ₃ . Hereinafter, examples of the present invention will be described in comparison with comparative examples. [Example] 800 cc of barium chloride aqueous solution (1.6 / mol concentration) and 900 cc of zinc chloride aqueous solution (1.8 / mol concentration) were mixed. Hydrolysis was performed by maintaining the mixed aqueous solution at 100 ° C. for 100 hours to obtain a sol containing Ba ²⁺ and Zn ²⁺ . This was washed, dried, and calcined at 1100 ° C. to prepare a BaZnO ₂ powder. The powder 10
g (0.0426 mol of BaZnO ₂ ) and 16.816 g of commercially available BaCO ₃ powder (0.
0852mol), Nb ₂ O ₅ powder 9.059g (0.0341mol), Ta ₂ O ₅ powder
3.765 g (0.00852 mol) was mixed with a ball mill for 24 hours and then calcined again at 1000 ° C. for 1 hour to obtain Ba (Zn _1/3 Nb _8/15 T
a _2/15 ) O ₃ powder was obtained. The particle size was about 0.4 μm. A tablet obtained by molding the powder at 1 t / cm ² was dried at 1400 ° C. in air for 2 hours.
Fired for hours. Table 1 shows the properties of the obtained BZNT ceramics. (Comparative Example) A commercially available BaCO _3, ZnO as a comparative _{example, Nb 2 O 5, Ta 3} O 5 powder of Ba
(Zn _1/3 Nb _8/15 Ta _2/15 ) O ₃ , so that BaCO ₃ −
25.224 g (0.1278 mol), ZnO-3.467 g (0.0426 mol), Nb
₂ O ₅ −9.059 g (0.0341 mol), Ta ₂ O ₅ −3.765 g (0.00852 mol
l) was mixed and mixed for one day in a ball mill and then fired at 1200 ° C. for one hour. The particle size of the calcined powder was about 1.2 μm. The powder was molded at 1 t / cm ² and fired under the same conditions as in the example. The characteristics are shown in Table 1. As can be seen from Table 1, the BZNT-based ceramics produced by the method of the present invention has a remarkably higher density than that of the conventional method, whereby the Q value is remarkably improved. In addition, the Q value is achieved at the same time as the ε _r value higher than that of the conventional material, and the superiority of the method of the present invention is further enhanced in the combination of both characteristic values of the Q value and ε _r value. [Effects of the Invention] According to the method of the present invention, by the steps (1) and (2)
Powder containing one or more of the components of BZNT (denatured powder)
Submicron particles with very few secondary particles can be formed, and by using this, a submicron class BZNT raw material powder can be easily obtained by a simple dry method thereafter. BZNT ceramics can be obtained. In addition, the following effects can be obtained. 1) Since a denatured powder obtained by calcination is sufficiently dispersed, it can be supplied as a raw material powder without particularly requiring a step of pulverizing the calcined product. 2) The BZNT powder obtained from the calcined denatured powder by a dry method is also obtained in a monodispersed state, and therefore has sufficiently high sinterability and high-density characteristics even without a pulverizing step. 3) As a dielectric resonator material for microwaves requiring extremely high density and high Q value, BZNT ceramics can be simply solid-phased by omitting operations such as hot pressing and HIP (for example, hot gas pressure sintering). By sintering, a high density very close to the theoretical density can be obtained. 4) BZNT of any composition can be supplied at extremely low cost by mass-producing modified powder having excellent powder properties.

Claims (1)

(57) [Claims] The chemical formula is Ba (Zn _1/3 Nb _{x / 3} Ta _{(2-X) / 3} ) O ₃ , 0
(1) A solution containing an appropriate amount of at least one metal component other than Zn in the chemical formula and Zn, and a solution other than Ba in the chemical formula. (2) preparing a solution containing an appropriate amount of at least one metal component and Ba, or a solution containing an appropriate amount of at least one metal component other than Nb in the chemical formula and Nb; A step of producing a sol by hydrolysis of the sol, drying the sol, and calcining at 700 to 1300 ° C. to form a calcined product. (3) The calcined product and the compound of the remaining components of the perovskite composition , And calcining at 700 to 1300 ° C to obtain a calcined powder; and (4) a step of molding the calcined powder and calcining at 1200 to 1700 ° C. Method of manufacturing container materials. 2. 2. The method according to claim 1, wherein in the step (1), an aqueous solution or an alcohol solution of the compound of the metal component is mixed with an aqueous solution or an alcohol solution of a compound of Zn, Ba, or Nb. 2. The method for producing a dielectric resonator material according to claim 1. 3. The Zn compound is zinc chloride, zinc sulfate, zinc nitrate,
3. The method for producing a dielectric resonator material according to claim 2, comprising one or more of zinc acetate and zinc acetate. 4. The Ba compound, barium chloride, barium chlorate,
3. The method for manufacturing a dielectric resonator material according to claim 2, comprising one or more of barium perchlorate, barium nitrate, barium acetate, barium ethylate, and barium isopropylate. 5. 3. The method for manufacturing a dielectric resonator material according to claim 2, wherein said Nb compound is composed of one or more of niobium chloride, niobium methoxide, niobium ethylate, and sodium niobate. . 6. In at least one of the steps (2) and (3), Zr, Mg, Sc, Hf, Th, W, Nb, Ta, Cr, M
Claims 1 characterized in that a trace amount of one or more of o, Ti, Mn, Fe, Co, Ni, Cd, Al, Sn, As, Bi, Zn, and Sr is added. Item 6. The method for producing a dielectric resonator material according to any one of Items 5 to 5. 7. The aid is _{BaZrO 3, BaSnO 3, SnTiO 3} , and a manufacturing method of one or scope sixth claim of claims, characterized in that it is added in a small amount in two or more forms dielectric resonator material BaTiO ₃ .